The New York authorities were scrambling to contain an angry backlash yesterday after police shot a group of three unarmed black men, killing one of them on his wedding day.

The shooting took place after a stag party at a strip club in Queens, a few hours before Sean Bell, 23, was due to marry the mother of his two small daughters. He was struck in the neck and arm and was dead on arrival at hospital.

One of his friends, Joseph Guzman, was in a critical condition after being hit 11 times, and another, Trent Benefield, was in a stable condition with wounds to his leg and buttocks.

Outrage at the shooting was compounded when it emerged that Mr Guzman and Mr Benefield had been shackled to their beds. New Yorkers have also been startled at the apparent wildness of the fusillade. The police claim to have overheard one of three men mention a gun, but no weapon was found.

The officers on the scene fired a total of 50 bullets, but fewer than half hit the intended target, a car carrying the three men, despite being fired at close range. The rest sprayed nearby cars and buildings, as local residents leapt out of bed and huddled on the floor. One of the stray bullets shattered a window at a train station in the neighbourhood, injuring two transport police officers with flying glass.

The shooting quickly became political with the appearance of community leaders - including the Reverend Al Sharpton, the black civil rights leader who has led previous protests against police brutality - alongside the victims' relatives outside the hospital where the wounded men were being treated. "I will stand with this family," Mr Sharpton said. "This stinks."

New York's mayor, Michael Bloomberg, urged patience, saying it was too early to draw conclusions. "We know that the officers on the scene had reason to believe an altercation involving a firearm was about to happen and were trying to stop it," he said.

Richard Brown, the borough's district attorney, promised a "full, fair and complete investigation".

New York officials' greatest fear is a repeat of the Amadou Diallo affair in 1999, from which the city's race relations took years to recover. Diallo was a Guinean immigrant who was killed in a hail of 41 police bullets after he reached for his wallet at the entrance to his block of flats. The four white officers involved in that incident were all acquitted of wrongdoing.

In Saturday's shooting, the police who opened fire were a mixed group, two white, two black and one Hispanic, and the circumstances were less clear cut. According to the police commissioner, Raymond Kelly, a fight broke out outside the Club Kalua in the Jamaica district of Queens, and one of the stag party group shouted "Yo, get my gun". According to an undercover officer on the scene, Mr Bell then said, "Let's fuck him up", referring to a man involved in the scuffle.

The club was under surveillance by a unit looking for evidence of prostitution, illegal guns and drug dealing.

One of the undercover officers alerted other policemen staking out the club, saying: "It's getting hot on Liverpool [a local street] for real. I think there's a gun." The officer followed Mr Bell and his friends as they got into their Nissan Altima.

"As the undercover officer approached the front of the car, the car moved forward, striking the undercover [officer]," Commissioner Kelly said. "It then ploughed into the front of the police minivan that had just turned south of Liverpool street. The driver of the Altima put the car in reverse and drove backward on to the sidewalk, slamming into a roll-down gate of the building there, close to where the undercover officer was located. The driver put the car into forward and rammed the police minivan a second time."

That is when the shooting started. One of the officers who jumped out of the minivan, a 12-year veteran, fired 31 shots, emptying two magazines of his 9mm pistol. Another let off 11 bullets. All the police on the scene were armed with 9mm automatic pistols and none had been involved in any previous shooting incident.

Yesterday, the silver Nissan stood where it came to rest against the police minivan and the road around it was sown with little flags marking bullet casings and other evidence. The reception hall where Mr Bell had been due to marry his high school sweetheart was still festooned with satin and balloons.

Robert Porter, Mr Bell's cousin who was due to be the DJ at the wedding, said 250 people had flown in from around the country for the event. "I can't really express myself. It's a numb feeling," Mr Porter said. "I still don't want to believe it, a beautiful day like this, and he was going to have a beautiful wedding, he was going to live forever with his wife and children. And this happened."

Targeted

Rodney King March, 1991 Twenty six year-old black man brutally beaten by officers after resisting arrest for speeding; a bystander, George Holliday, videotaped attack. Acquittal of the LAPD officers led to riots in May 1992. King given $3.8m.

Amadou Diallo, February 1999 Street trader from Guinea, shot 19 times when white NYPD officers mistook his wallet for a gun and fired 41 bullets. Four officers acquitted; family paid $3m compensation.

Timothy Thomas, April 2001 Unarmed black 19-year-old, shot by a white officer, Stephen Roach, in Cincinnati. Was wanted for traffic violations and was fleeing. Roach was acquitted. Eight hundred arrests made in ensuing riots.